
<style>
    html{
        width: 100vw;
        height: 100vh;
        background-image: linear-gradient( 45deg, #0fd850 0%, #f9f047 100%);
    }

    form{
        position: absolute;
        top: 30%;
        left: 40%;
        border: 1px solid purple;
        padding: 30px;
        border-radius: 6px;
    }

</style>

<span>
    <?php
    echo $_SESSION["msg"];
    $_SESSION["msg"]=null;
    ?>
</span>

<form action="doLogin.php" method="post">
    <label>
        用户名：
        <input name="userName">
    </label> <br>
    <label>
        密 &nbsp; 码：
        <input name="userPwd" type="password">
    </label> <br>
    <input type="reset"> <input type="submit" value="登录">
    <button type="button" onclick="window.location.href='register.php'" >去注册</button>
</form>